The 17 pound vellum is very easy to work with, although it is limited. It is only suitable for embossing, which is made easier by being such a
thin material. The only time I pierce this paper is for sewing it on a
backing.
This paper is very translucent, making it perfect for adding color with pastels on the back side of an embossed design. When using this technique, you need to leave open spaces for the color to show through in your design. The effect is similar to cliossoné. If you make a more solid embossed design with any of the Border templates and wrap the vellum around a backing paper, it looks like brocade!
I also find this paper very handy for sketching out altered patterns.
You can find larger quantities of this vellum online at Marco's Paper. For larger than 8.5" x 11" go to Reich Paper.